Various resins such as an epoxy resin, a cyanate ester resin, a bismaleimide-triazine resin, and a benzoxazine resin have been used as a resin material for an electronic component used for a semiconductor sealing material and an insulating layer for a multilayer printed board, and in recent years, in various applications, particularly in most-advanced electronic materials applications, materials and compositions which realize further improvement in performance such as heat resistance and dielectric properties and exhibit low moisture absorptivity have been required.
Among them, benzoxazine, which can be easily prepared by combining a phenol compound, an amine compound, and formaldehyde, undergoes ring-opening polymerization by heating by itself, and exhibits high heat resistance and low linear expansion due to a strong hydrogen bonding structure formed in a crosslinked structure. From this reason, nawadays, the benzoxazine is not only examined for the above-mentioned application of electric materials, but also attracts attention as a resin material for next generation devices typified by SiC power semiconductors.
As benzoxazine in the related art, benzoxazines prepared from a bifunctional phenol such as bisphenol F and bisphenol A and aniline are disclosed in PTL 1 and PTL 2. However, since an aniline-derived component is generated as a decomposed gas at the time of ring-opening of oxazine, the thermal decomposition resistance which is an index of long-term thermal durability has not reached a level required in recent years, and thus further improvement and performance improvement are strongly desired.